As printing and ink technology improve, ink based printing machines are being used to print on a larger variety of objects and mediums other than paper. Printing on paper is a fairly straight forward process as paper has a typically flat and even surface. As a result, a print head can maintain an optimal print head gap to the paper during printing.
A proper print head gap is one of the factors that determines how well the image can be printed onto a medium. When the print head gap between the print head and the medium being printed on is not optimal, influences acting on the ink droplets or degradation of the ink droplets may reduce image quality. For example, the farther away the print head and surface being printed on are, the greater the loss of image quality.
Printing onto contoured or profiled surfaces can be challenging. Objects that have an irregular surface, or uneven geometry, may have non-parallel or non-coplanar conditions between the print head and the surface of the medium or part that is receiving the ink droplets. As a result, printing on irregular surfaces using traditional ink based printing machines may suffer in poor image quality due to the variation of print head gap.